diff --git a/wp-admin/includes/misc.php b/wp-admin/includes/misc.php
index 24cfd2cb8b..666bfdbfc5 100644
--- a/wp-admin/includes/misc.php
+++ b/wp-admin/includes/misc.php
@@ -523,36 +523,6 @@ function saveDomDocument($doc, $filename) {
 	fclose($fp);
 }
 
-/**
- * Workaround for Windows bug in is_writable() function
- *
- * @since 2.8.0
- *
- * @param string $path
- * @return bool
- */
-function win_is_writable( $path ) {
-	/* will work in despite of Windows ACLs bug
-	 * NOTE: use a trailing slash for folders!!!
-	 * see http://bugs.php.net/bug.php?id=27609
-	 * see http://bugs.php.net/bug.php?id=30931
-	 */
-
-	if ( $path[strlen( $path ) - 1] == '/' ) // recursively return a temporary file path
-		return win_is_writable( $path . uniqid( mt_rand() ) . '.tmp');
-	else if ( is_dir( $path ) )
-		return win_is_writable( $path . '/' . uniqid( mt_rand() ) . '.tmp' );
-	// check tmp file for read/write capabilities
-	$should_delete_tmp_file = !file_exists( $path );
-	$f = @fopen( $path, 'a' );
-	if ( $f === false )
-		return false;
-	fclose( $f );
-	if ( $should_delete_tmp_file )
-		unlink( $path );
-	return true;
-}
-
 /**
  * Display the default admin color scheme picker (Used in user-edit.php)
  *
diff --git a/wp-includes/functions.php b/wp-includes/functions.php
index f541c787b4..e51c155ed1 100644
--- a/wp-includes/functions.php
+++ b/wp-includes/functions.php
@@ -1408,6 +1408,36 @@ function get_temp_dir() {
 	return $temp;
 }
 
+/**
+ * Workaround for Windows bug in is_writable() function
+ *
+ * @since 2.8.0
+ *
+ * @param string $path
+ * @return bool
+ */
+function win_is_writable( $path ) {
+	/* will work in despite of Windows ACLs bug
+	 * NOTE: use a trailing slash for folders!!!
+	 * see http://bugs.php.net/bug.php?id=27609
+	 * see http://bugs.php.net/bug.php?id=30931
+	 */
+
+	if ( $path[strlen( $path ) - 1] == '/' ) // recursively return a temporary file path
+		return win_is_writable( $path . uniqid( mt_rand() ) . '.tmp');
+	else if ( is_dir( $path ) )
+		return win_is_writable( $path . '/' . uniqid( mt_rand() ) . '.tmp' );
+	// check tmp file for read/write capabilities
+	$should_delete_tmp_file = !file_exists( $path );
+	$f = @fopen( $path, 'a' );
+	if ( $f === false )
+		return false;
+	fclose( $f );
+	if ( $should_delete_tmp_file )
+		unlink( $path );
+	return true;
+}
+
 /**
  * Get an array containing the current upload directory's path and url.
  *